Total Posts: 258
Your store has been put in maintenance mode. If Magento sees a file named ‘maintenance.flag’ in the root directory, it will automatically redirect all requests to the default 503 error page.
Delete or rename ‘maintenance.flag’ in the Magento root directory. Then you should clear the cache.
If the site doesn’t still work, please, read the following information.
You need to go to your site via FTP and then go to the Magento directory app/etc/modules, there are all the files which enable/disable all the extensions. You need to find the file, which has in its name the extension name, which has been installed by you, and rename it. The files are named the same as “CompanyName_ExtensionName.xml” You can add an emphasis at the end of such a file and clear the cache. It will disable the extension.